The idea of utilizing biological attributes of
ecosystems as indicators of quality is a relatively old one and
it actually has been fairly well developed for use in streams and
rivers in such states as Ohio, North Carolina, and Maine. The
impetus for such work has arisen from concern over the declining
quality of water resources in the US over the past several
decades and associated with this concern, some strong federal
legislation, most notably the Clean Water Act passed in 1977,
which mandates States to safeguard their water resources.

Here in Hawaii, one of the major lessons
learned from what has come to be called the 'Waiahole
Controversy', is that we are ill-equipped to deal with water
resource protection and conservation issues, particularly with
regard to the allocation disputes which inevitably will arise
when there are competing uses for a finite resource. For those of
you from out-of-state, the controversy in this case is the
classic one, with large landowners tugging on one side of the
rope for water to develop their lands and stimulate the economy
and on the other end of the rope, the small subsistence user
demanding that water be returned to their stream to protect rural
lifestyles and maintain habitat for native species. A crucial
environmental question being asked is, 'How much water should be
left in the stream to protect native species and maintain natural
function?' This is followed with the corollary question, 'How
would we know that the negotiated level of conservation flow
actually improved stream quality over time?'

In order to address these crucial questions, we
must first of all be able to measure the condition of the
resource and then be able to assess improvement or impairment of
that resource as a result of the decisive management action. The
approach that has shown remarkable success in other states, is
the use of narrative and numeric biological criteria or
biocriteria, as it is perhaps better known, that describe the
preferred biological condition of aquatic communities. Trying to
agree upon what is the preferred condition, however, can get
pretty sticky when opposing parties each bring their own experts
to the table. And this, in fact, is what happened in the Waiahole
deliberations. We, therefore, must first agree upon some standard
and my suggestion, is that we adopt as this standard of Hawaiian
stream quality, the condition of the native components in a
stream as indicators of the functioning ecosystem. In this
standard, then, we focus on native species as well as the
functional aspects of their environment which keep them healthy.

How, then, could this standard integrated into
biocriteria, be applied to assess and monitor the impacts of
these diverse uses of the Hanalei River on Kauai island? Implied
in the term biocriteria is the notion of comparison to the
highest attainable condition. This concept therefore incorporates
the reality that that there are no more biologically pristine
ecosystems, streams or otherwise, left in Hawaii. The general
approach is to use minimally impacted streams to provide
reference conditions. For Hawaii, this would mean that we would
use the best streams on each island as a basis for developing a
set of biological attributes, or metrics, which will be used to
measure water quality. Biotic integrity for Hawaiian streams
would be conceptually defined as the most robust native aquatic
community expected in a natural condition and biocriteria will be
used to protect these resource values. In this system, natural or
minimally impaired water resource conditions, therefore, become
the criteria for judgment and management

The metrics that are chosen to assess biotic
integrity must not only reflect community characteristics but
also change in predictable ways with increased human influence.
In other words, two sets of metrics are required, one which
contrasts the elements of the ecosystem with functional
relationships and a second set, which measures the degradative
effects of human activities on the resident biota. The challenge
in implementing biocriteria is to develop reliable and
cost-effective ways to quantify these attributes using carefully
selected representative taxa. The end-product of this work will
be a set of quantified metrics obtained through standardized
protocols which will yield a single, ecologically-based index of
water resource quality.

One of the problems that we have been
struggling with lately in our assessment work has to do with
making biotic comparisons in streams which may differ drastically
in physical attributes. Do streams which differ significantly in
flow velocities, oxygen saturation, and dominant substrate type,
for example, differ naturally in biotic attributes as well? Can
we compare streams across islands for these biotic attributes
using some statewide set of metrics? Judging from some recent
work that we've done comparing physical and chemical attributes
of sites at similar elevations on Onomea and Alakahi Streams on
the Big Island with Limahuli Stream on north Kaua'i, that answer
appears to be, MAYBE NOT. Streams within-islands or
island-regions appear to have certain characteristic signatures
of hydrology and physiography that may govern their biotic
attributes. Physical metrics, therefore, should be incorporated
into protocols for standardization and reference conditions may
need to be developed for regional streams within-islands or
groups of islands.

On this map are located study sites on Kauai
streams where we have applied standardized assessment protocols
over the past several years. These data will be used as a basis
for examining the range of suitable metrics. GIS or Geographical
Information System displays, like this one and others used
throughout this presentation, demonstrate the usefulness of this
system as a powerful tool for resource management application in
Hawaii.

One of the advantages of working in Hawaiian
streams for biocriteria development, is the simplified nature of
its native components and the fact that, for most taxa anyway, we
can readily distinguish natives from aliens. Focusing on flowing,
wadable Hawaiian streams for now, leaving aside deep estuaries
which will require a separate set of metrics, the abundances and
composition of populations of our native stream fish species,
known locally as 'o'opu, are obvious choices for community
metrics. These species are readily distinguishable and respond to
varying degrees, inter-specifically, to human intervention. While
we have made advances in understanding their functional roles,
and have put considerable effort into developing robust methods
of quantifying their densities, there is still much we need to
learn about their population dynamics.

For example, we know little about temporal
variation in population structure or the factors which influence
such variation. In Kalalau Stream on Kauai's Na Pali coast 'o'opu
populations are structured in definite patterns with certain
species exhibiting higher densities in certain elevational
segments until all fish disappear above around 250 meters in
elevation. For our fish metrics to be meaningful, then, we need
to get a better handle on the dynamics of population change and
then incorporate this in some fashion into the metrics that we
choose to use.

Fish condition and the relative abundances of
alien fish species in streams provide potential metrics for
assessing biotic impairment. Huge die-offs of native oopu
chronically occur in de-watered stream reaches which are preceded
by rampant disease in the population. In degraded streams native oopu
are often infested with Myzobdella lugubris, an alien
freshwater leech, which attach to their fins and eyes and are
agents of disease and mortality. Bill Font, from Southeastern
Louisiana University, has connected the infestation of native oopu
with Asian tapeworms to high densities of alien poeciliids
(Poeciliidae), such as swordtails (Xiphophorous helleri),
which are becoming more common now in many of Hawaii's streams.
While poeciliids were introduced into Hawaii for mosquito
control, I'm not sure why anyone in their right mind would want
to introduce Tilapia mossambica into Hawaiian streams but
people have and now this aggressive cichlid (Cichlidae) from
Africa preys upon and competes directly with native oopu
for food and space. Higher scores on these metrics would,
obviously, correlate with increased impairment and therefore
lower stream quality.

Many states also incorporate metrics using
indicator insect taxa such as EPT, which stands for the insect
orders Ephemeroptera-Plecoptera-Tricoptera, none of which include
species native to Hawaiian streams. Based on our intensive
sampling of swift-water habitat in a variety of streams over the
years, it turns out that most of the insect biomass now collected
off the stream bottom in Hawaii, are three alien species; a
midge, Cricotopus bicinctus (Diptera: Chironomidae) and
two caddisfly species, Cheumatopsyche pettiti (Tricoptera:
Hydropsychidae) and Hydroptila arctia (Tricoptera:
Hydroptilidae). Since their introductions, these aliens have
spread throughout Hawaii and now dominate swift-water stream
habitat. Our diet studies on native stream fishes, interestingly,
have shown that these alien insects are now used by them as food,
particularly in the case of the o'opu-nakea. Although
alien species, they may be useful as indicators of biotic
impairment as they do seem to be intolerant of reduced flow,
chemical pollution, and low dissolved oxygen.

Certain native macroinvertebrates are good
candidate indicator taxa. Native mountain shrimp, opae kalaole,
as well as the native stream snail, hihiwai, are more
abundant in higher quality streams and appear to be quite
sensitive to sedimentation, dewatering and low oxygen. For
insects, Dan Polhemius (formerly with Bishop Museum now with the
Smithsonian Institute) has suggested incorporation of a
'torrenticlous guild' which I'll call T-S-P for Telmatogeton
spp., Scatella spp, and Procanace spp., as a
metric. Flies from at least one of these endemic genera are
nearly always present in moderate to excellent quality stream
habitat and they appear to be extremely sensitive to flow
reduction. Similarly, the presence of native odonates,
damselflies and dragon flies, suggest high stream quality and
therefore are also probably effective indicator taxa. Quantifying
the abundances of these invertebrates, however, is notoriously
difficult and we have been testing traps and other devices for
their efficacy in sampling protocols.

Algae have been infrequently used in assessment
programs for a variety of reasons yet for Hawaiian streams,
anyway, they may be an important functional metric. Our diet
studies have shown, for example, that algae provide the bulk of
the food for all native stream fishes. From the little we know of
their ecology, most immature forms of native aquatic insects
appear to utilize algae for food, shelter, or in various phases
of their development. This possibly new Telmatogeton
species, for example, builds its pupal case within and feeds upon
this green alga identified as Cladophora glomerata. Our
benthic data also indicates that certain algal species are common
in unaltered stream habitat which suggests that, as with fish and
invertebrates, we may be able to find suitable indicator algal
species. Two possibilities are this green alga you see here, Cladophora
glomerata and a blue-green Nostoc verrucosum. There
may be other algae, such as Spirogyra sp. and Ulothrix
sp., which are more abundant in dewatered or degraded conditions
and these may then be useful in a series of algal metrics that
measure impairment.

There is good reason to be concerned about the
quality of Hawaii's freshwater resources for, after all, we do
live on islands and depend upon these finite resources for our
very survival. Streams inter-connect the terrestrial landscape to
the marine environment and we must recognize this as we shift our
emphasis away from saving single species to the conservation of
functional island ecosystems. We must also somehow come to grips
with our society's seemingly insatiable need for more water.
Perhaps the place to start, is to recognize that the water that
sustains us in our island ecosystem and the water that sustains
native stream organisms are one and the same, and by protecting
one, we can also protect the quality of the other.